Hedera Guardian through 3.5.1 contains an authentication bypass vulnerability in the GET /api/v1/demo/registered-users endpoint that allows unauthenticated attackers to retrieve sensitive user information. Attackers can access the endpoint without providing authentication credentials to obtain usernames, Hedera DIDs, parent registry DIDs, system roles, and policy role assignments for all registered users in the system.

A Stored Cross-Site Scripting vulnerability was discovered in the Assets and Nodes functionality due to improper validation of an input parameter. An authenticated user with custom fields privileges can define a malicious custom field containing a JavaScript payload. When the victim views the Assets or Nodes pages, the XSS executes in their browser context, allowing the attacker to perform unauthorized actions as the victim, such as modify application data, disrupt application availability, and access limited sensitive information.

An access control vulnerability was discovered in the Threat Intelligence functionality due to a specific access restriction not being properly enforced for users with view-only privileges. An authenticated user with view-only privileges for the Threat Intelligence functionality can perform administrative actions on it, altering the rules configuration, and/or affecting their availability.

Hashgraph Guardian through version 3.5.0 contains an unsandboxed JavaScript execution vulnerability in the Custom Logic policy block worker that allows authenticated Standard Registry users to execute arbitrary code by passing user-supplied JavaScript expressions directly to the Node.js Function() constructor without isolation. Attackers can import native Node.js modules to read arbitrary files from the container filesystem, access process environment variables containing sensitive credentials such as RSA private keys, JWT signing keys, and API tokens, and forge valid authentication tokens for any user including administrators.